The present invention relates to a display apparatus able to detect external proximate objects. More particularly, the present invention relates to a display apparatus with touch detection functions that detect touch on the basis of changes in capacitance, as well as to a driving method for such an apparatus, and to an electronic device provided with such an apparatus.
In recent years, display apparatus such as liquid crystal display (LCD) apparatus have become equipped with touch detection functions that detect external proximate objects, such as fingers. Attention is being focused on display apparatus that enable information input by causing various button images or other elements to be displayed on such display apparatus, which works as a substitute for ordinary mechanical buttons. Since display apparatus that include such touch detection functions can be operated without input apparatus such as a keyboard, mouse, or keypad, their usage is being expanded to computers and even to devices such as mobile phones and similar mobile information terminals.
Several touch detection techniques exist. One such technique is the capacitive technique. For example, Japanese Unexamined Patent Application Publication No. 2009-244958 discloses a display apparatus wherein a common electrode already provided in the display apparatus for display purposes is also used as one half of a pair of touch sensor electrodes. The other electrode (i.e., the touch detection electrode) is disposed intersecting the common electrode. A capacitance is formed between the common electrode and the touch detection electrode, and this capacitance will change in response to an external proximate object. Consequently, the display apparatus is configured to detect external proximate objects by analyzing a touch detection signal appearing at the touch detection electrode when a driving signal for touch detection is applied to the common electrode. In this display apparatus, display operation is carried out by conducting a line-sequential scan (i.e., a display scan), similarly to a typical LCD apparatus. Additionally, touch detection operation is carried out by successively applying the above driving signal for touch detection to the common electrode and conducting a line-sequential scan (i.e., a touch detection operation).
Meanwhile, in recent years, design and other factors have led to a desire to decrease the width of the area running along the outer edge of the active display area (i.e., the bezel or frame area). This demand is particularly strong with respect to mobile information terminals, where the factors of portability and ease of use have led to demand for more compact devices. As a result, it has become important to decrease the bezel width of the display apparatus provided in such mobile information terminals.
In the display apparatus disclosed in JP-A-2009-244958 cited above, the display scan and the touch detection operation run in the same direction, and there are provided a plurality of touch detection electrodes that extend in the direction of these scans. In order for the touch detection signals output from these touch detection electrodes to be transmitted to a touch detection circuit, space is provided for signal retrieval and circuit pattern routing. Consequently, the bezel width might increase in those areas. In other words, the bezel width increases along the edge that intersects the display scan direction.
More specifically, in a landscape display apparatus, for example, the display scan is conducted while moving down along the short edge direction. For this reason, the touch detection electrodes are provided extending in the short-edge direction, and a plurality of touch detection signals are output from the long edge on one side. When mounting such a display apparatus into a module, a flexible substrate or similar technology is used for the signal retrieval and circuit pattern routing disposed in order to transmit this plurality of touch detection signals to the touch detection circuit. As a result, the bezel width is increased along the long edge.
Being devised in light of such problems, embodiments of the present invention provide a display apparatus with touch detection functions, a driving method, and an electronic device that enable the bezel width to be decreased along the edge that intersects the display scan direction.